I am assuming you are indeed talking about the root password. I have not used ImageWriter before, so forgive me.

scriptham wrote:Can anyone explain what is going on please?

The root password on the LiveCD is, to my knowledge, not documented. This makes it impossible to login as the root user in Live mode (for security purposes, I assume). However, sudo works just fine. Note that sudo will not prompt for a password, so use it with caution.

scriptham wrote:How do I get to run ImageWriter please?

Open a terminal and type "sudo imagewriter" without quotes. This will allow you to run imagewriter with superuser privileges. If that does not work, you can try "sudo su -c imagewriter" without quotes. It all depends on how the program works. You should then be able to use ImageWriter without any issues.